Nut lock



April 21, 1931. V J. LADD NUT LOCK Filed Dec. 28. 1929 INVENTOR i, ATTORNEY 40 f th structure Shown i Fi be brought into the position in which it is $0 Patented Apr. 21, 1931 V UNITED STATES. PATENT OFFICE JAMES B. LADD, OI ARIDMORE, PENNSYLVANIA Application filed December 28,1929. Serial No. 417,047.

This invention relates to means for lock Fig. is a plan view on anenlarged ing cooperating threaded elements, such as scale of the locking pawl shown in Fig. 5. V a nut to a bolt for thepurpose of holding Fig. 16 is an elevation of the structure the nut from working loose, and refers parshown in Fig. 15, partly in section.

0 ticularly to means for holding a nut against Fig. 17 is a plan view on an enlarged 5 rotation in either direction up to a predeterscale of still another form of locking pawl mined rotary torque. and another form of pivoting means. i

In one form, the invention comprises an Fig. 18 is an elevation of the structure improved construction of thelocking means shown in Fig. 17, partly in section.

0 so as to' have same entirely within the nut Similar numerals refer to similar parts 13.; with no part'exposed to injury from contact throughout he Sev ral Views. with other nuts or the like, either before or Broadly described, my invention com after being put in service, prises a pawl movably connected with a pin Other objects and advantages of the consecured in anut, the pawl adapted to move struction will be seen from the description angularly with respect to h i 0f the nut following and the accompanying drawings, and solocated and confined that when the which illustrate, merely-by way ofexample, nut 1s turned onto the bolt its free end will suitable embodiments of the invention, be bIOllghl? into fOl'CiblB 001113301; With. the

Fi 1 i a l i f: a t on a b lt thread on the bolt and will resist the rota- :ID ith a lo ki wl Shown, in d tt d fines tion. of the nut 1n the reverse direction up Fig, 2 i a, a t ti n, t, l ti f to a predetermined torque, and will yield th d vi shown in Fi 1, when the torque is increased above the pre- Fi ,3 i l n i h i a determlned amount and be moved angularly difi ti r by the reverse rotation of the'nut into a p0 ll 4 is a, part section part elevation of SJ-171011 which it IBSlSt the 'IOtatlOIl T5 the structure shown in Fig. 3. the 11111? 1 the opposite direction.

Fig. 5 is a plan view showing a further 111 ge a When a 1111i? 20 h y kdifi ti v i mg device is put on a bolt 21, with a right- Fi 6 i a t ti t l ti hand thread, the pawl 22 will automatically Fig. 7 is a plan view on an enlarged scale $W1i sy the rotation of the nut f th l ki l Shown i Fi 1 d in the direction of the arrow shown, and if th i on hi h it m the nut isforcibly turned in the reverse di- Fig. 8 is an elevation of the structure rectum l PF W b moved around into 4! shown in Fig. 7 partly n Section the positlon 111 which it is shownin F ig- ,3. 1

Fig. 9 is a Plan view on an enlarged scale The i in of Prefer-red embod of another form of locking pawl and the i z 1S q f j slot i as cut p on which it turns. lato thp nut ili light alrri gles Yltll 61th; axlsflof t e nu as siown 1n igs. an or e i H a q of t Structure slot may be of the formshown in F 3, or 9 s FY m f m Sec cut from the inside of the nut as shownin 11 1S P an Vlew an enlarged Fig.5, or otherwise. But the pawl may be Scale another ml of lockmg p and located entirely without the nut as shown in the pin on whlch 1t turns.

Fig. 12, and this construction is preferred 4; Fig. 12 is an elevatlon of the structure t ti I 95.

shown in'Fig. 11, partly in section. Generally the pawl is formed with an eye, Fig. 13 is a plan view on an enlarged such as 24., at one end, and a pin such as 25, scale of still another form of locking pawl. passing through this eye, is used to locate Fig. 14 is an elevation of the structure and confine said end; but the end of the shown in Fig. 13,v partly in section. pawl may be cylindrical in form as at 26,

shown in Figs. 9, ll, 13, 15 and 17;

and it may be confined by a tubular or channelled formation such as 25, as shown in Fig. 17 Accordingly when the term pin is used hereinafter it shall be understood to include a solid pin such as shown in Figs. 7 to 16 inclusive, or a hollow or a tubular pin such as shown in Figs. 17 or 18, or the equivalent.

In accordance with my invention, the pawl is always free to more around its pin, through a slight angle to and from either side of a line drawn through its in and the center of the nut, but its free angular motion is positively limited by means such as shown in Fig. 7, where a tit or projection 27 on the inside of the eye on the pawl extends into a recess in the pin, or by other means of properly disposed stops such as shown in Figs. 3, 5, 11, 15 and 17.

hen the pawl is at the limit of its free angular movement in either direction, its free end 29 extenes into the threaded hole or bore of the nut, and when the nut is rotated onto the bolt, said free end is forced beyond said angular position and is brought into forcible contact with the thread onthe bolt. This final movement, beyond its free angular movement, results in the ileXure of the pawl when a pawl is used of the form or, where the arrangement is such as shown in Figs. 7 and 8, wherethe free movement of the pawl is limited by a tit or projection within the eye of the pawl engaging with a slot in J the pin, the pin is subject to torsion when the free angular motion of the pawl is exceeded. In this case the pin is shown reduced in cross section above and below the pawl to give the desired torsional resistance to the movement of the pawl, but such reduction in cross section may not be used. It is to be noted that in all cases one end of the pin is rigidly secured against rotation, as shown in Figs. 2, 4 and 6, or otherwise, while there is always a limited relative rotative movement between the pawl and its pin.

hen the nut has been rotated on the bolt in the direction of the arrow, as in Fig. l, and the pawl is forcibly in contact with the thread on the bolt, it is evident that if the nut is rotated in the reverse direction the pawl must pass a radial position in passing over to the position shown in Fig. 3, and therefore, to permit the pawl to be forced by the rotation of the nut from the position shown in Fig. 1 to the position shown in F i 3, it is essential that the pawl must be shortened lengthwise if the pin is rigid, or the pin must be moved radially away from the bolt if the pawl is rigid and does not yield to the compressive strain upon it.

When arigid pin is used, a shortening of the pawl is obtained by using a pawl of resilient material in form such, for example, as shown in Figs. 9, 13, 15 and 17, which will yield to compressing strain in the direction of its length; and when a pawl rigid a ainst compression (such as shown in Figs. and 11) is used, a pin of resilient material adapted to yield to transverse strain is used, such as shown in Figs. 8 and 12.

Particular attention is called to the pawls shown in Figs. 9, 13, 15 and 17, as such pawls are of resilient material adapted to yield to compressive strain in direction of their length, and also to yield by fiexure to the transverse strain to which they will be subjected when their free ends are forced past the extremes of the free angular motion permitted. It will also be noted that the combined resilience of the pawl and of its pin may be utilized as in Figs. 9 and 10.

The free end of the pawl which contacts with the thread on the bolt is preferably of a cylindrical form as shown in Figs. 7 and 8, but may be of any form adapted to holding the nut against rotation, either by friction or by biting into the thread, or both.

lVhat I claim is:

1. A. device for looking a nut to a belt or the like comprising a pawl pivotally mounted on a pin seated in the nut with its axis approximately parallel with the bore of the nut, the pawl normally extending from said pin into the bore of the nut, one of said members being resilient to permit said pawl to be snapped to either side of a line connecting said pin and the center of said bore, and means limiting the free angular movement of the pawl to a small angle to either side of said line, said limiting means causing the free end of the pawl to forcibly engage the thread on the bolt when it is snapped by the rotation of the nut to either limit of its free angular motion.

2. A device for looking a nut to a bolt, comprising a pivoted pawl, and a pin therefor of resilient material mounted on the nut to yield by fiexure when subjected to transverse strain by the pawl.

JAMES B. LADD. 

